Polyphenols based on isoflavones as inhibitors of Helicobacter pylori urease

Evaluation of Geranium spp., Helleborus spp. and Hyssopus spp. polyphenolic extracts inhibitory activity against urease and α-chymotrypsin

“…The hydroxyl groups presented on aromatic ring of polyphenol molecule may be responsible for the inhibitory activity by coordinating with the nickel (active site) of the enzyme 30 . Flavonoids can also chelate metal ions [31][32][33] and thus inhibit urease activity; quercetin, kaempferol, apigenin and luteolin have been reported to exhibit inhibitory activity against urease 18 . The TPCs content in H. purpurascens polyphenolic extract was lower, but this extract was rich in tannins, while G. robertianum polyphenolic extracts showed a high value for TPC, but the lowest tannin content value.…”

Potent genistein derivatives as inhibitors of estrogen receptor alpha-positive breast cancer

“…(br s, 2H), 4.15-4.05 (m, 4H), 3.62-3.50 (m, 4H), 1.55-1.41 (br s, 18H); FABMS (m/z): (M + Na + : 578.9). (19). Diamine 18 (0.12 g, mmol) in 15 mL of TFA:DCM (2:1) was stirred at room temperature for 12 h. The reaction mixture was concentrated and the crude product was recrystallized in Ethylacetate to yield product 19 (0.053 g 70%) as solid.…”

“…hence, to enhance the anticancer activity of genistein at lower concentrations, we have synthesized seven structurally modified derivatives of genistein (Ma-6, Ma-8, Ma-11, Ma-19, Ma-20, Ma-21 and Ma-22) based on the structural requirements for an optimal anticancer effect. among those seven, three derivatives (Ma-6, Ma-8 and Ma- 19) showed high antiproliferative activity with IC 50 levels in the range of 1-2.5 μM, i.e., at much lower concentrations range than genistein itself, in three eR-positive breast cancer cell lines (MCF-7, 21pT and T47D) studied. In our analysis, we noticed that at IC 50 concentrations, the Ma-6, Ma-8 and Ma-19 genistein derivatives induced apoptosis, inhibited eRα messenger RNa expression and increased the ratio of eRβ to eRα levels in a manner comparable to the parent compound genistein.…”

“…Compounds 1-20 were synthesized based on the schemes 1-4. Phloroglucinol was treated with 4-hydroxy phenyl acetonitrile in the presence of dry HCl to yield compound 1, 19 which underwent internal clyclization with PCl 5 to give compound 2 (genistein). Hydroxy functionalities of compound 2 underwent alkylation using 1,2-dibromoethane in the presence of base, yielding di-and mono-alkylated compounds 3 and 4, respectively.…”

Role of Natural Antioxidants in Gastritis

“…Helicobacter pylori induces gastric epithelial cell apoptosis via secreted mediators such as the VacA cytotoxin and lipopolysacccharides which damage epithelial acid-secreting parietal cells (Neu et al, 2002). Several flavonoids have inhibitory influence on the apoptotic signaling induced by Helicobacter pylori VacA toxin (Xiao et al, 2007). Antimicrobial compounds from plants may inhibit bacterial growth by different mechanisms and could therefore be useful in case of resistance state to antibiotics.…”